Over the years considerable work has been devoted to fuel performance additives for controlling (preventing or reducing), among other factors, deposit formation in fuel induction systems of spark-ignition internal combustion engines. In particular, additives that can effectively control fuel injector deposits, intake valve deposits, and combustion chamber deposits are often the focus of research activities and, despite these efforts, further improvements are frequently desired particularly in view of further advances in engine technology for improving fuel economy and engine wear.
One component of a typical fuel performance additive is a detergent. The role of the detergent is often to control the formation of intake valve deposits and injector deposits in internal combustion engines, as well as reduce or minimize the formation of deposits in the combustion chamber or remove existing deposits. The detergents are often utilized in combination with fluidizers or fluid carriers to improve the performance of the detergent. To enhance the detergent's ability to control deposits, detergents conventionally were added to fuels in conjunction with petroleum-based or synthetic carrier fluids. Petroleum-based carrier fluids include naphthenic and paraffinic base stock oils, and conventional synthetic fluids include low molecular weight polypropylenes, polyisobutylenes, poly-alpha olefins, esters, polyols, and polyalkyleneoxides. In recent years, the use of mineral oils as carriers has been reduced or eliminated due to their contributions to combustion chamber deposits.
While incorporating detergents and carriers in fuels has been effective in reducing intake valve deposits, the carrier fluid itself typically had little to no detergent activity. The carrier fluid aided in the dispersal of the detergent and often provided a fluidizing property to the fuel. Carrier fluids, in many applications, often include a relatively large portion of the additive package; thus, any reduction or improvement in carrier fluid technology can have significant effects on the performance and costs of the fuel performance additive.